1. Field of the Invention
This invention relates to a brake control apparatus and a brake control method for use in a vehicle.
2. Description of Related Art
An anti-lock brake system (ABS) has been proposed to suppress the locking of the wheels during braking of a vehicle, which is designed such that if locked wheels or slip is detected, control is performed to automatically relax the braking. In addition, an automatic braking system has also been proposed which is designed to brake a running vehicle independently of the driver's braking operation if required, for example when an obstacle is detected in front of the vehicle. Further, Japanese Patent Application Publication No. 2002-160623 (JP 2002-160623 A) describes a vehicle anti-skid control system, which changes the condition to start anti-skid control according to whether or not a brake force is applied to wheels by an automatic braking system. This system thereby prevents the control amount at the start of anti-skid control from being increased to cause drastic change in the brake force due to the fact that the anti-skid control is not started until brake slip becomes higher than when normal anti-skid control is started.
When an automatic braking system is used to brake a vehicle as necessary independently of the driver's braking operation, sufficient safety must be ensured for the driver. Therefore, the association in activation between an ABS and an automatic braking system must be improved more.